Merge order in Armada 370/XP (mvebu) NAND support
Hello,
Now that all the pxa3xx-nand code has been merged by proper maintainers and is available in each subsystem's trees I'd like to ask for suggestions regarding a potential problem.
Since v3.12, the pxa3xx-nand driver supports the "armada370-nand" compatible. This was probably a mistake as little to no NAND support is present in that release.
The support to handle 4K pages devices (for instance, supporting the Mirabox board) was submitted later, and is currently in MTD tree, waiting to be pulled in v3.14.
On the other side, the devicetree files (dts and dtsi) needed to enable such support was taken through the mvebu tree. Currently, a board booted using mvebu's for-next branch will try to probe the NAND device (because the compatible was merged in v3.12) and there's a chance it hits on of NAND core's BUG().
The patchset containing the devicetree changes was prepared under the assumption that the driver would be merged first, so no risk existed.
I admit this was a crappy assumption on my side to make (and worse:
it's not the first time I assume this).
Jason/Brian: What do you think we can do?
Signature · 3 lines
Ezequiel Garc?a, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com
Quoted 1 line · Ezequiel Garcia
Jason/Brian: What do you think we can do?
Revert the change adding the compatible string in the first place?
thx,
Jason.
Quoted 5 lines · Jason Cooper
Quoted 1 line · Ezequiel Garcia
Jason/Brian: What do you think we can do?
Revert the change adding the compatible string in the first place?
Yes, that probably is the best thing to do.
Brian: what do you think? I can send you a revert of the "armada370-nand" compatible addition to be pushed for v3.13-rc4?
The compatible can be added on top of l2-mtd.git, after all the needed support is in the driver.
Signature · 3 lines
Ezequiel Garc?a, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com
Quoted 10 lines · Ezequiel Garcia
Quoted 4 lines · Jason Cooper
Quoted 1 line · Ezequiel Garcia
Jason/Brian: What do you think we can do?
Revert the change adding the compatible string in the first place?
Yes, that probably is the best thing to do.
Brian: what do you think? I can send you a revert of the "armada370-nand" compatible addition to be pushed for v3.13-rc4?
Yes, I think dropping the "armada370-nand" compatible string would be a good solution for 3.13. Are there any use cases where "armada370-nand" is needed and operational on 3.12? (e.g., is 2KB page support fine?) Because if there are *no* valid use cases for compatible = "armada370-nand" yet, then we might want this to go to 3.12.y stable as well, right?
Quoted 2 lines
The compatible can be added on top of l2-mtd.git, after all the needed support is in the driver.
Sure.
I'll take a look at your "revert" patch and see if we can get it upstream for 3.13.
Thanks,
Brian